An autonomous vehicle is a vehicle that is capable of sensing its environment and navigating with little or no user input. An autonomous vehicle senses its environment using sensing devices such as inertial measurement units, radar, LIDAR, image sensors, and the like. The autonomous vehicle system further uses information from global positioning systems (GPS) technology, navigation systems, vehicle-to-vehicle communication, vehicle-to-infrastructure technology, and/or drive-by-wire systems to navigate the vehicle.
Vehicle automation has been categorized into numerical levels ranging from Zero, corresponding to no automation with full human control, to Five, corresponding to full automation with no human control. Various automated driver-assistance systems, such as cruise control, adaptive cruise control, and parking assistance systems correspond to lower automation levels, while true “driverless” vehicles correspond to higher automation levels.
Inertial measurement units (IMUs) are devices that use inertial sensors such as accelerometers and gyroscopes to measure how a body, or in this case the vehicle, moves. IMUs are a main component of inertial navigation systems and may measure force, rotational attributes such as pitch, roll, and yaw, to allow for the vehicle to navigate.
In order to obtain accurate information from the IMU, the IMU must be calibrated with respect to the vehicle and the environment surrounding the vehicle. In some instances the calibration is performed when the IMU is installed to the vehicle. Over time, the calibration may become inaccurate or “drift.” Accordingly, it is desirable to provide systems and methods for aligning an IMU of a vehicle. It is further desirable to provide methods and system for aligning the IMU in realtime. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.